class MeioTransporte:
    def __init__(self, combustivel = "gasolina"):
        self.combustivel = combustivel
        self.__privado = True
    def __str__(self):
        return "combustivel =" + str(self.combustivel)

class Carro(MeioTransporte):
    def __init(__self, combustivel):
        MeioTransporte.__init__(self, combustivel = "gasolina")
    def __str__(self):
        return MeioTransporte.__str__(self)

obj = Carro("gasoleo")

print isinstance(obj, MeioTransporte)
print issubclass(Carro, MeioTransporte)
try:
    print obj.__privado
except AttributeError:
    print "__privado e uma variavel privada"
